Compliant balloon with liquid injection

Abstract

A system and method for occluding a pulmonary vein. The device includes a treatment device comprising an inner balloon, an outer balloon, and a space therebetween. Delivery of fluid to the inner balloon inflates the treatment element to a first diameter. If a greater treatment element diameter is required to completely occlude a pulmonary vein, fluid is delivered to the space between the first and second balloons, which expands the second balloon and causes the treatment element to have a second diameter that is greater than the first diameter. The fluid delivered to the inner balloon and fluid delivered to the space between the balloons may be from different sources and may be delivered and exhausted independently. Once the treatment element is caused to have a diameter sufficient to completely occlude the pulmonary vein, the treatment element is activated to cool or heat ostial tissue.

What is claimed is: 
     
       1. A medical system for treating cardiac arrhythmia within a patient's heart, the system comprising:
 a console including:
 a first fluid reservoir containing a non-cryogenic inflation fluid; 
 a second fluid reservoir containing a cryogenic coolant; and 
 a computer in communication with the first and second fluid reservoirs; 
 
 a treatment device including:
 an elongate body defining a lumen; 
 a treatment element coupled to the elongate body having a first balloon and a chamber having a length, and a second balloon coupled to the elongate body and being disposed about the first balloon, the first balloon and the second balloon defining an interstitial space therebetween; and 
 a first fluid injection lumen in fluid communication with the chamber and the first fluid reservoir, and a second fluid injection lumen in fluid communication with the interstitial space and the second fluid reservoir; and 
 
 a mapping device including a plurality of mapping elements and being slidably movable within the treatment device lumen, the mapping device further including a flexible distal end that is configurable into a loop that is in contact with an inner surface of a pulmonary vein such that a diameter of the loop determines an inner diameter of the pulmonary vein, the mapping device being in communication with the computer, 
 the computer being programmed to:
 inflate the first balloon to a first maximum outer diameter at a widest point of the first balloon by the non-cryogenic inflation fluid delivered to the chamber from the first fluid reservoir through the first fluid injection lumen, the first maximum outer diameter being less than an inner diameter of the pulmonary vein; 
 calculate the inner diameter of the pulmonary vein based on the size of the mapping element loop; 
 predict a diameter of an ostium of the pulmonary vein based on the calculated inner diameter of the pulmonary vein; and 
 expand the second balloon to a second maximum outer diameter at a widest point of the second balloon by the cryogenic coolant delivered to the interstitial space by the second fluid reservoir through second fluid injection lumen, the cryogenic coolant within the interstitial space separating the first balloon and the second balloon a distance apart along the entire length of the chamber, the second maximum outer diameter being greater than the first maximum outer diameter, being based on at least one of the calculated inner diameter of the pulmonary vein and the predicted diameter of the ostium of the pulmonary vein, and being sufficient to occlude the pulmonary vein. 
 
 
     
     
       2. The medical system of  claim 1 , wherein the treatment device further includes one or more sensors on the treatment element. 
     
     
       3. The medical system of  claim 2 , wherein the one or more sensors are pressure sensors. 
     
     
       4. The medical system of  claim 3 , wherein the second maximum outer diameter corresponds to an inner diameter of a pulmonary vein ostium within the patient's heart, the diameter of the pulmonary vein ostium being determined at least in part by signals from the one or more pressure sensors. 
     
     
       5. The medical system of  claim 1 , wherein the second balloon is substantially compliant. 
     
     
       6. The medical system of  claim 5 , wherein the first balloon is substantially noncompliant. 
     
     
       7. The medical system of  claim 4 , wherein the first balloon is composed of a shape memory material. 
     
     
       8. The medical system of  claim 1 , wherein the non-cryogenic inflation fluid is selected from the group consisting of: water, contrast medium, saline, and a mixture thereof. 
     
     
       9. The medical system of  claim 1 , wherein the cryogenic coolant is a liquid. 
     
     
       10. The medical system of  claim 1 , wherein the treatment device further comprising a fluid injection element disposed within the chamber. 
     
     
       11. The medical system of  claim 1 , wherein the treatment device further comprising a heating element disposed within the chamber. 
     
     
       12. The medical system of  claim 6 , wherein the second balloon has a uniform wall thickness. 
     
     
       13. The medical system of  claim 6 , wherein the second balloon has one or more portions having a first wall thickness and one or more portions having a second wall thickness. 
     
     
       14. A medical system for occluding a pulmonary vein, the medical system comprising:
 a treatment element including a first balloon defining a chamber defining a length and a second balloon being disposed about the first balloon, the first balloon and the second balloon defining an interstitial space therebetween; 
 a first fluid injection lumen in fluid communication with the chamber and a second fluid injection lumen in fluid communication with the interstitial space and 
 a mapping device extending distally beyond the treatment element, the mapping device including a flexible distal end that is configurable into a loop that is in contact with an inner surface of the pulmonary vein such that a diameter of the loop determines an inner diameter of the pulmonary vein; 
 a controller being programmed to: 
 inflate the first balloon to a first maximum outer diameter at a widest point of the first balloon by a non-cryogenic inflation fluid delivered to the chamber from the first fluid injection lumen, the first maximum outer diameter being less than an inner diameter of the pulmonary vein, 
 expand the second balloon to a second maximum outer diameter at a widest point of the second balloon by a cryogenic coolant delivered to the interstitial space by the second fluid injection lumen, the cryogenic coolant within the interstitial space separating the first balloon and the second balloon a distance apart along the entire length of the chamber, the second maximum outer diameter being greater than the first maximum outer diameter; 
 determine the second maximum outer diameter based on the diameter of the loop of the mapping device to sufficiently occlude the pulmonary vein. 
 
     
     
       15. The medical device of  claim 14 , wherein the cryogenic coolant is a liquid. 
     
     
       16. The medical device of  claim 15 , further comprising a plurality of pressure sensors on the second balloon. 
     
     
       17. The medical device of  claim 16 , wherein the cryogenic coolant is at a temperature that causes ablation of tissue. 
     
     
       18. A method of occluding a pulmonary vein, the method comprising:
 positioning a mapping element including a distal loop within the pulmonary vein such that the distal loop is in contact with an inner circumference of the pulmonary vein, a diameter of the distal loop determining an inner diameter of the pulmonary vein: 
 positioning a treatment element in contact with an ostium of the pulmonary vein, the treatment element including a first balloon defining a chamber having a length, a second balloon being disposed outside of the first balloon, and an interstitial space defined between the first and second balloon; 
 delivering a non-cryogenic inflation fluid to the chamber to inflate the first balloon and cause the treatment element to have a first maximum outer diameter at a widest segment of the first balloon; 
 determining, based on the diameter of the distal loop, a second maximum outer diameter at a widest segment of the second balloon that would completely occlude the ostium of the pulmonary vein; and 
 then delivering a cryogenic coolant to the interstitial space to expand the second balloon to cause the treatment element to have the second maximum outer diameter at a widest segment of the second balloon to completely occlude the ostium of the pulmonary vein, the delivery of the cryogenic coolant to the interstitial space expanding the second balloon such that the second maximum outer diameter is greater than the first maximum outer diameter, the cryogenic coolant within the interstitial space separating the first balloon and the second balloon a distance apart along the entire length of the chamber. 
 
     
     
       19. The method of  claim 18 , wherein the chamber is in fluid communication with a first fluid injection lumen and a first fluid recovery lumen and the interstitial space is in fluid communication with a second fluid injection lumen and a second fluid recovery lumen. 
     
     
       20. The method of  claim 19 , further comprising:
 after delivering the cryogenic coolant to the interstitial space to expand the second balloon, determining whether the pulmonary vein is completely occluded; and 
 ablating at least a portion of the ostium when it is determined that the pulmonary vein is completely occluded. 
 
     
     
       21. The method of  claim 20 , wherein the cryogenic coolant is delivered from the second fluid injection lumen and evacuated by the second fluid recovery lumen. 
     
     
       22. The method of  claim 20 , wherein the cryogenic coolant within the interstitial space has a temperature sufficient to cause ablation of tissue. 
     
     
       23. The method of  claim 18 , wherein the treatment element further includes a plurality of pressure sensors on an outer surface of the second balloon, the plurality of pressure sensors recording at least one of pressure signals generated by contact between the plurality of pressure sensors and the pulmonary vein and pressure signals generated by a lack of contact between the plurality of pressure sensors and the pulmonary vein. 
     
     
       24. The method of  claim 23 , wherein an amount of the cryogenic coolant delivered to the interstitial space to expand the second balloon is determined at least in part on the pressure signals recorded by the plurality of pressure sensors. 
     
     
       25. The method of  claim 24 , wherein the amount of cryogenic coolant is delivered to the interstitial space in fixed-volume increments.